Mooring Systems for Very Large Floating Structures

Owing to scarcity of land, very large floating structures (VLFS) are now being designed to cater for the increase in population and growth of coastal areas. The applications of VLFS include floating piers, floating airports, floating bridges, floating fuel storage facilities and even floating cities. One of the key design aspects of VLFS is the mooring design. Mooring design of VLFS is a challenge due to huge size of the structures, environmental loads, shallow water depths, space constraint for mooring lines and anchor installation. There are additional challenges pertaining to transportation of blocks, integration onsite and design allowance for possible future expansion of the VLFS. This paper examines the hydrodynamic and mooring design of a typical VLFS. The relevant concepts, motion response, mooring design and design criteria will be presented. The mooring design will incorporate sensitivity studies on different material choices for mooring lines. Chains, wire ropes and polyester (Dyneema) will be considered for the mooring design. The chain mooring system is compared with piles mooring system. Additional issues pertaining to installation and future expansion of VLFS will be discussed.